A consist includes one or more locomotives that are coupled together to produce motive power for a train of rail vehicles. The locomotives each include one or more engines, which combust fuel to produce mechanical power. The engine(s) of each locomotive can be supplied with liquid fuel (e.g., diesel fuel) from an onboard tank, gaseous fuel (e.g., natural gas) from a tender car, or a blend of the liquid and gaseous fuels. The mechanical power produced by the combustion process is directed through a generator and used to generate electricity. The electricity is then routed to traction motors of the locomotives, thereby generating torque that propels the train. The locomotives can be connected together at the front of the train or separated and located at different positions along the train. For example, the consist can be positioned at the front, middle, or end of the train. In some instances, more than one consist can be included within a single train. The locomotives in a consist can be oriented in a forward-facing (or “long hood”) direction or a backward-facing (or “short hood”) direction. In some consists, the locomotives include computer systems for maintaining operations of the locomotive. These computer systems are sometimes disposed on the long hood side of the locomotive.
Because the locomotives of a consist must cooperate to propel the train, communication between the locomotives can be important. Historically, this communication has been facilitated through the use of an MU (Multi-Unit) cable that extends along the length of the consist. An MU cable is comprised of many different wires, each capable of carrying a discrete signal used to regulate a different aspect of consist operation. For example, a lead locomotive generates current within a particular one of the wires to indicate a power level setting requested by the train operator. When this wire is energized, the engines of all trail locomotives are caused to operate at a specific throttle value. In another example, when one locomotive experiences a fault condition, another of the wires is energized to alert the other locomotives of the condition's existence.
In some consists, locomotives communicate via their respective computer systems on an Ethernet network formed over the MU cables. With this configuration, network data can be transmitted from the computer system in the lead locomotive to the computer systems in the trail locomotives, and vice-versa. The network data includes data that is packaged as data packets and uniquely addressed to particular computer systems, or portions of the computer systems. The network data can be, for example, vehicle sensor data indicative of vehicle health, commodity condition data, temperature data, weight data, and security data. The network data is transmitted orthogonal to conventional non-network (i.e., command) data that is already being transmitted on the MU cable.
For some operations, the order of locomotives within the consist can be important. For example, each locomotive within the consist may set their throttles according to their respective positions within the consist. Traditionally, locomotive consist order is determined and set manually by a human operator, but this method can be prone to error as locomotives are sometimes moved from one consist to another and the human operator may forget or neglect to reset a locomotive's position within the consist. One method of determining locomotive consist order using a computer is described in U.S. Pat. No. 5,986,577 (the '577 patent) issued to Bezos on Nov. 16, 1999. The '577 patent describes a system and method for determining the position of each railroad vehicle within a train consist. Each vehicle in the consist has a vehicle computing device. A computer on a locomotive sequentially commands each vehicle computing device. When a command is sent to a vehicle computing device, all of the other vehicle computing devices located between the locomotive and the commanded vehicle computing device sense an electrical signal carrying the command and respond to the computer on the locomotive. The computer, after having commanded all of the vehicle computing devices and having received the responses, automatically determines the position of each railroad vehicle relative to all other railroad vehicles within the train consist.
Although the system of the '577 patent attempts to determine locomotive consist order, the system is prone to error. For example, the system of the '577 patent determines locomotive consist order with respect to one locomotive in the consist and with one data set collected by that one locomotive, causing the system to be susceptible to errors. For example, when a consist has adjacent locomotives coupled long hood to long hood, the system of the '577 patent may determine they are in the same consist position because the distance between the computers of the adjacent locomotives is close, causing data from either of the adjacent locomotives to appear to have originated from the other. Further, the system of the '577 patent can be prone to error because response time of the individual vehicle computing devices can vary, causing inconsistent or inaccurate results.
The disclosed system is directed to overcoming one or more of the problems set forth above.